Prior studies have shown that plant-based diets are associated with lower cardiovascular risk. However, these diets encompass a large diversity of foods with contrasted nutritional quality that may differentially impact health. We aimed to investigate the pooled cross-sectional association between metabolic syndrome (MetS), its components, and healthy and unhealthy plant-based diet indices (hPDI and uPDI), using data from two French cohorts and one representative study from the French population. This study included 16,358 participants from the NutriNet-Santé study, 1,769 participants from the Esteban study and 1,565 participants from the STANISLAS study who underwent a clinical visit. The MetS was defined according to the International Diabetes Federation definition. The associations between these plant-based diet indices and MetS were estimated by multivariable Poisson and logistic regression models, stratified by gender. Meta-analysis enabled the computation of a pooled Prevalence Ratio. A higher contribution of healthy plant foods (higher hPDI) was associated with a lower probability of having MetS (PRmen: 0.85; 95% CI: 0.75–0.94, PRwomen: 0.72; 95% CI: 0.67–0.77), elevated waist circumferences and elevated blood pressure. In women, a higher hPDI was associated with a lower probability of having elevated triglycerides, low HDL-cholesterolemia and hyperglycemia; and a higher contribution of unhealthy plant foods was associated with a higher prevalence of MetS (PRwomen: 1.13; 95% CI: 1.01–1.26) and elevated triglycerides. A greater contribution of healthy plant floods was associated with protective effects on metabolic syndrome, especially in women. Gender differences should be further investigated in relation to the current sustainable nutrition transition.

Despite the urgent need for plant-based dietary shifts, few studies have examined current diet trajectories using longitudinal data. This study analyzed dietary transitions of French adults over 8 years (2014-2022), assessing diet quality and the role of various socio-economic factors. Consumption data from 17 187 NutriNet-Santé cohort participants, weighted for the French Census, were collected via FFQ in 2014, 2018 and 2022. Adopting a gender-specific approach, consumption changes in twenty-three food groups were assessed over time. Diet quality was evaluated using the Comprehensive Diet Quality Index score, categorising foods into ‘healthy’ and ‘unhealthy’. Socio-economic analysis targeted four food groups (red meat (including fresh beef, pork, offal and lamb), processed meat (e.g. sausages, ham and bacon), legumes and whole-grain products), strongly linked to mortality risk and recognised as significant markers of the sustainable diet transition. All analyses were conducted using multi-adjusted mixed-effects models. Consumption of some healthy plant-based foods (nuts +59 %, legumes +22 %, whole-grain products +7 %) significantly increased over time, while consumption of some unhealthy foods (red meat −19 %, refined cereals −18 %, sweetened drinks −15 %) decreased. Conversely, consumption of prepared and mixed dishes (+16 %) and processed meat (+35 %) increased. These changes differed in magnitude between genders and translated into an improved diet quality score (Comprehensive Diet Quality Index). Occupational status was linked to longitudinal changes in food consumption, showing increased consumption of plant-based foods among students and higher socio-professional categories. Our findings provide accurate data on trends and factors for targeted initiatives, guiding strategic interventions for a sustainable dietary transition.

Childbirth is a major life-changing event, this period is an opportunity to improve eating habits. The aim of this longitudinal study was to identify and characterise dietary changes in women according to their parity status. Dietary intake data from 4194 women of childbearing age included in the NutriNet-Santé cohort were derived using a FFQ, administered in 2014 and 2018, distinguishing between organic and conventional food consumption. Women were classified into four groups: ‘previous children’, ‘multiparous’, ‘primiparous’ and ‘nulliparous’. Multi-adjusted ANCOVA models were used to estimate the changes according to the parity group. Changes in food consumption towards a more plant-based, healthier and organic diet were observed in all four groups of women, although to various degrees. In multivariable models, ‘Nulliparous’ women showed a greater improvement in terms of ‘sustainable’ food consumption than ‘previous children’ women. ‘Primiparous’ women significantly increased their energy intake (+349 (269–429) kcal/d) and their consumption of dairy products (+30 (3–56) g/d), and they significantly decreased their consumption of alcohol (–23 (–32–15) g/d), coffee and tea (–107 (–155–60) g/d). Regarding organic food, ‘nulliparous’ women increased their consumption more than ‘previous children’ and ‘primiparous’ women were those who were most frequently in the top quintile of organic food increase. Although there were dietary changes in all groups of women according to their parity, childless women have a shift moving towards a more sustainable diet. Women who had a first child reduced their alcohol and caffeine consumption.

The Mediterranean diet is often proposed as a sustainable diet model. This study aimed to evaluate the associations between adherence to the Mediterranean diet and sustainability domains in a cohort of French adults, using multiple criteria including nutritional quality, environmental pressures, monetary cost and dietary pesticide exposure. Food intakes of 29 210 NutriNet-Santé volunteers were assessed in 2014 using a semi-quantitative FFQ. Adherence to the Mediterranean diet was evaluated using the validated literature-based adherence score (MEDI-LITE). The associations between the MEDI-LITE and various sustainability indicators were examined using ANCOVA models, adjusted for sex, age and energy intake. Higher adherence to the MEDI-LITE was associated with higher nutritional quality scores, better overall nutrient profile as well as reduced environmental impact (land occupation: Q5 v. Q1: −35 %, greenhouse gas emissions: −40 % and cumulative energy demand: −17 %). In turn, monetary cost increased with increasing adherence to the Mediterranean diet (Q5 v. Q1: +15 %), while higher adherents to the Mediterranean diet had overall higher pesticide exposure due to their high plant-based food consumption. In this large cohort of French adults, greater adherence to the Mediterranean diet was associated with nutritional and environmental benefits, but also with higher monetary cost and greater exposure to pesticides, illustrating the necessity to develop large-scale strategies for healthy, safe (pesticide- and contaminant-free) and environmentally sustainable diets for all.

Non-communicable diseases, such as cancers and CVD, represent a major public health concern, and diet is an important factor in their development. French dietary recommendations were updated in 2017, and an adherence score, the Programme National Nutrition Santé Guidelines Score (PNNS-GS2), has been developed and validated using a standardised procedure. The present study aimed to analyse the prospective association between PNNS-GS2 and the risk of death, cancer and CVD. Our sample consisted of French adults included in the prospective NutriNet-Santé cohort (n 67 748, 75 634 and 80 269 for the risk of death, cancer and CVD, respectively). PNNS-GS2 (range: –∞ to 14·25) was calculated from the 24-h dietary records of the first 2 years of monitoring. Association between PNNS-GS2 (in quintiles, Q) and the risk of death, cancer and CVD was studied using Cox models adjusted for the main confounding factors. The sample included 78 % of women, aged on average 44·4 years (sd 14·6) with on average 6·6 (sd 2·3) dietary records. Average PNNS-GS2 was 1·5 (sd 3·4) and median follow-up was 6·6 years for cancers and 6·2 years for CVD and deaths. PNNS-GS2 was significantly associated with the risk of death (hazard ratio (HR)Q5vsQ1: 0·77 (95 % CI 0·60, 1·00), 828 cases), cancer (HRQ5vsQ1 = 0·80 (95 % CI 0·69, 0·92), 2577 cases) and CVD (HRQ5vsQ1 0·64 (95 % CI 0·51, 0·81), 964 cases). More specifically, PNNS-GS2 was significantly associated with colorectal and breast cancer risks but not prostate cancer risk. Our results suggest that strong adherence to the 2017 French dietary recommendations is associated with a lower risk of death, cancer or CVD. This reinforces the validity of these new recommendations and will help to promote their dissemination.

While food-based dietary guidelines have been widely disseminated for decades to improve nutritional knowledge in the population about healthy diets, more recent interventions such as front-of-pack labelling have made the differences between the two approaches apparent. While food-based dietary guidelines provide the overarching framework and benchmarks for a healthy diet, based on the current knowledge of the associations between various dietary components and health outcomes, front-of-pack labelling provides guidance to select a specific food, either within a food group or among similar foods belonging to various brands. Labelling foods as ‘healthy’ or ‘unhealthy’ raises multiple questions on the criteria used to define the terms and the implications of assigning an absolute healthiness value to an individual food in the context of complex diets. Gradual systems may provide more relative assessments and avoid dichotomisation. The present article presents the inherent differences and the complementarity of food-based dietary guidelines and food choice guidance in the context of food labelling.

In France, dairy products contribute to dietary saturated fat intake, of which reduced consumption is often recommended for CVD prevention. Epidemiological evidence on the association between dairy consumption and CVD risk remains unclear, suggesting either null or inverse associations. This study aimed to investigate the associations between dairy consumption (overall and specific foods) and CVD risk in a large cohort of French adults. This prospective analysis included participants aged ≥18 years from the NutriNet-Santé cohort (2009–2019). Daily dietary intakes were collected using 24-h dietary records. Total dairy, milk, cheese, yogurts, fermented and reduced-fat dairy intakes were investigated. CVD cases (n 1952) included cerebrovascular disease (n 878 cases) and CHD (n 1219 cases). Multivariable Cox models were performed to investigate associations. This analysis included 104 805 French adults (mean age at baseline 42·8 (sd 14·6) years, mean follow-up 5·5 (sd 3·0) years, i.e. 579 155 person-years). There were no significant associations between dairy intakes and total CVD or CHD risks. However, the consumption of at least 160 g/d of fermented dairy (e.g. cheese and yogurts) was associated with a reduced risk of cerebrovascular diseases compared with intakes below 57 g/d (hazard ratio = 0·81 (95 % CI 0·66, 0·98), Ptrend = 0·01). Despite being a major dietary source of saturated fats, dairy consumption was not associated with CVD or CHD risks in this study. However, fermented dairy was associated with a lower cerebrovascular disease risk. Robust randomised controlled trials are needed to further assess the impact of consuming different dairy foods on CVD risk and potential underlying mechanisms.

Although micronutrient deficiencies affect 2 billion people worldwide, no index focuses on measuring the risk of overt nutrient deficiency. We aimed to develop an index that could capture the nutrient dimension of nutritional security, a nutrient security index (named SecDiet), and evaluate its apparent validity. The SecDiet (range: 0–1) is based on the square-weighted average of the probabilities that the intake of twelve critical nutrients exceeds the threshold value associated with a risk of overt deficiency. Using adult populations from a French representative survey (INCA3, n 1774) and a large cohort (NutriNet-Santé, n 104 382), the content and construct validity of the SecDiet was evaluated by estimating associations of the SecDiet with its components and with relevant socio-demographic characteristics. The SecDiet was high in the overall population (0·93 (SD 0·09) in INCA3) and markedly skewed towards 1 (i.e. lower risk of insufficient intake). It correlated positively with its twelve components (r 0·17–0·78, all P < 0·001). The SecDiet was associated with monthly income (P = 0·002), perception of financial situation, professional situation, food insufficiency and security statuses (all P < 0·001) in the INCA3 population and with monthly income, professional situation and level of education (all P < 0·001) in the NutriNet-Santé population. Unlike a broader nutrient-based quality index taken as comparison, the SecDiet mean decreased and the tail of its distribution notably extended downwards in at-risk sub-populations, thus revealing its specific sensitivity. The SecDiet could be used to screen sub-groups or study the determinants of nutrient insecurity in large population surveys.

Organic food consumption and its effects on health remain understudied in adults and in children. The aim of this study was to describe family characteristics associated with feeding infants organic foods during the complementary feeding period. The analysis included 9764 children from the French Étude Longitudinale Française depuis l’Enfance (ELFE) birth cohort. In addition to telephone interviews conducted at 2, 12 and 24 months, a monthly questionnaire about milk feeding and complementary foods (including organic foods) was completed by parents between 3 and 10 months. Associations between family characteristics and feeding with organic foods during complementary feeding were analysed by multivariable multinomial logistic regression. Overall, 51 % of infants never consumed organic food during the complementary feeding period (up to 10 months), 24 % sometimes, 15 % often and 9 % always or almost always. As compared with infants never fed organic foods, those ‘often’ or ‘always’ fed organic foods were born to older mothers, with higher education level or family income, and lower pre-pregnancy BMI. As compared with never-smoking women, women who had stopped smoking before pregnancy were more likely to feed their infant organic foods. Feeding with organic foods was also related to long breast-feeding duration and later introduction to complementary foods. To conclude, associations between feeding with organic foods and family socio-economic position as well as infant feeding practices need to be considered when studying the impact of organic foods on children’s health and development.

Host–microbial co-metabolism products are being increasingly recognised to play important roles in physiological processes. However, studies undertaking a comprehensive approach to consider host–microbial metabolic relationships remain scarce. Metabolomic analysis yielding detailed information regarding metabolites found in a given biological compartment holds promise for such an approach. This work aimed to explore the associations between host plasma metabolomic signatures and gut microbiota composition in healthy adults of the Milieu Intérieur study. For 846 subjects, gut microbiota composition was profiled through sequencing of the 16S rRNA gene in stools. Metabolomic signatures were generated through proton NMR analysis of plasma. The associations between metabolomic variables and α- and β-diversity indexes and relative taxa abundances were tested using multi-adjusted partial Spearman correlations, permutational ANOVA and multivariate associations with linear models, respectively. A multiple testing correction was applied (Benjamini–Hochberg, 10 % false discovery rate). Microbial richness was negatively associated with lipid-related signals and positively associated with amino acids, choline, creatinine, glucose and citrate (−0·133 ≤ Spearman’s ρ ≤ 0·126). Specific associations between metabolomic signals and abundances of taxa were detected (twenty-five at the genus level and nineteen at the species level): notably, numerous associations were observed for creatinine (positively associated with eleven species and negatively associated with Faecalibacterium prausnitzii). This large-scale population-based study highlights metabolites associated with gut microbial features and provides new insights into the understanding of complex host–gut microbiota metabolic relationships. In particular, our results support the implication of a ‘gut–kidney axis’. More studies providing a detailed exploration of these complex interactions and their implications for host health are needed.

The rising popular belief that gluten is unhealthy has led to growth in gluten avoidance in people without coeliac disease. Little information is available on their dietary profiles and their dietary behaviours. Our aim was to compare the consumption of organic foods between gluten avoiders and non-avoiders, and their places of food purchase. We described their sociodemographic and dietary profiles. The study population included participants of the NutriNet-Santé cohort who completed both a food exclusion questionnaire and an organic semi-quantitative FFQ (n 23 468). Food intake and organic food consumption ratios were compared using multivariable adjusted ANCOVA models. Associations between gluten avoidance and organic food consumption as well as places of food purchase were investigated with multivariable logistic regression. Participants avoiding gluten were more likely to be women and had a healthier dietary profile. Organic food consumption was higher among gluten avoiders (48·50 % of total diet for total avoiders, 17·38 % for non-avoiders). After adjustments for confounders, organic food consumption and purchase in organic stores were positively associated with gluten avoidance: adjusted OR (aOR)Q5 v.Q1 organic food = 4·95; 95 % CI 3·70, 6·63 and aORorganic stores v.supermarkets = 1·82; 95 % CI 1·42, 2·33 for total avoiders. Our study highlights that individuals avoiding gluten are high organic consumers and frequently purchase their foods in organic stores which propose an extended offer of gluten-free food. Further research is needed to determine the underlying common motivations and the temporality of the dietary behaviours of healthy people avoiding gluten.